Rip tides, harmful marine life and stormy weather are common dangers associated with the beach. But rescue officials want Miami-Dade residents to look out for another less-expected hazard: sand holes.

Miami-Dade Fire Rescue officers have noticed more and more cases around the country of sand caving in on top of beach-goers, which is why they decided to hold a demonstration Tuesday morning illustrating what could be a deadly end to a day at the beach. It hasn’t happened in Miami-Dade — yet — and officials hope they can keep it that way by spreading awareness.

Inside the hole, a mannequin sat upright, and a bulldozer was parked nearby with its blade pointed at the pile of displaced sand. Morizot explained that because sand is constantly shifting from erosion and weather conditions, the bottom of the hole could give way causing the walls to cave in.

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“Once the whole wall collapses on you, there is no way you can get out by yourself,” he said. “You need help.”

But even with the assistance of rescue personnel, people still lose their lives from suffocation. Morizot cited a study from a Harvard doctor that listed 52 victims over 10 years. Out of the victims, 31 people — or 60 percent — died from asphyxiation. The victims ranged from ages 3 to 21.

Morizot spoke of another incident from 2011, closer to home in Pompano Beach. A hole collapsed on a 19-year-old Austrian national swim team member after he jumped inside of it. The teen lived, but it took about 60 rescue officials to dig him out.

Back at Crandon Park on Tuesday, the bulldozer revved up then pushed the pile of displaced sand into the hole with the same amount of force had the sand caved in on its own. Sure enough, the mannequin was completely buried.

It took three fire rescue officials a little over three minutes to pull the mannequin out. The rescue was relatively short compared to other cases Morizot has heard of, one of which took 35 minutes to dig out a victim.

On Miami-Dade beaches patrolled by the fire rescue, lifeguards are trained to stop visitors from digging. But they can’t protect everyone, Morizot said, and he hopes beach-goers will quit the dangerous practice before it’s too late.

“The recommendation is do not dig whatsoever,” he said. “Enjoy the beach. Go in the water. But don’t dig.”